To activate a page, mark_page_accessed() always holds a reference on it. It either gets a new reference when adding a page to lru_pvecs.activate_page or reuses an existing one it previously got when it added a page to lru_pvecs.lru_add. So it can't call SetPageActive() on a page that doesn't have any reference left. Therefore, the race is impossible, not these days (I didn't brother to dig into its history). For other paths, namely reclaim and migration, a reference count is always held while calling SetPageActive() on a page. SetPageSlabPfmemalloc() also uses SetPageActive(), but it's irrelevant to LRU pages. Signed-off-by: Yu Zhao <yuzhao@xxxxxxxxxx> --- mm/memremap.c | 2 -- mm/swap.c | 2 -- 2 files changed, 4 deletions(-) diff --git a/mm/memremap.c b/mm/memremap.c index 03e38b7a38f1..3a06eb91cb59 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -451,8 +451,6 @@ void free_devmap_managed_page(struct page *page) return; } - /* Clear Active bit in case of parallel mark_page_accessed */ - __ClearPageActive(page); __ClearPageWaiters(page); mem_cgroup_uncharge(page); diff --git a/mm/swap.c b/mm/swap.c index de257c0a89b1..1f223a02549d 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -898,8 +898,6 @@ void release_pages(struct page **pages, int nr) del_page_from_lru_list(page, lruvec, page_off_lru(page)); } - /* Clear Active bit in case of parallel mark_page_accessed */ - __ClearPageActive(page); __ClearPageWaiters(page); list_add(&page->lru, &pages_to_free); -- 2.28.0.236.gb10cc79966-goog
